The largest opposition party in Turkey, the Republican People’s Party (CHP), has officially launched a request for a recount of votes in Sunday’s referendum to expand President Recep Tayyip Erdogan’s executive power.

Erdogan opponents in the country’s major cities have also taken their protests to the streets and the front door of the national election council.

CHP leaders approached the Turkish Supreme Election Board (YSK) Tuesday with a formal request to recount votes, citing a mid-day policy change by the YSK that legitimized unverified ballots. Enough unverified ballots made it through the final vote tally to have potentially flipped the vote, as the “yes” contingent won by only 51 percent to 49 percent for “no.”

The referendum asked Turks whether they would like to switch from the current parliamentary system to a presidential system, which would eliminate the prime minister’s office and grant that power to President Erdogan. Erdogan would also have the option of appointing one or several vice presidents, among other changes.

“We came here to defend the rights of all of society, not just ‘no’ voters,” CHP Deputy Chairman Erdal Aksünger said Tuesday at the YSK. “I told [the YSK] it was necessary to cancel the vote because there was a problem wth them.”

There is only one thing to do: to cancel this popular vote, which has lost its legitimacy,” Bülent Tezcan, another CHP leader, added.

In Ankara Tuesday, Kemal Kilicdaroglu, the head of the CHP, called the counting of unverified votes “a betrayal to democracy.”

The CHP announced on Monday it will seek to recount up to 60 percent of the votes. The YSK has insisted that the votes are legitimate, however. Sadi Guven, the head of the YSK, issued a statement calling the unverified ballots “YSK-made, real, legitimate, non-fake ballots.”

Independent election observers have sided with the minority parties. The Organization for Security and Cooperation in Europe (OSCE), which sent representatives to observe the vote, said in a statement that the “legal framework remained inadequate for the holding of a genuinely democratic referendum.”

“The referendum took place in a political environment in which fundamental freedoms essential to a genuinely democratic process were curtailed under the state of emergency, and the two sides did not have equal opportunities to make their case to the voters,” Tana de Zulueta, head of the ODIHR limited election observation mission, said. “Our monitoring showed the ‘Yes’ campaign dominated the media coverage and this, along with restrictions on the media, the arrests of journalists and the closure of media outlets, reduced voters’ access to a plurality of views.”

The Turkish Foreign Ministry issued a counter-statement calling the OSCE’s conclusions “unacceptable.” Turkish Foreign Minister Mevlut Cavusoglu also protested that one of the OSCE’s observers, German MP Andrej Hunko, had been photographed waving the flag of the Kurdistan Workers’ Party (PKK), a U.S.-designated Marxist terrorist organization, in 2014. The Turkish government continues its ongoing offensive to eliminate the group from the nation’s Kurdish-majority regions.

“How can one expect objectivity?” Cavusoglu asked.

Protesters in the urban areas where the “no” vote was most prevalent took to the streets Monday night, waving signs reading “Hayir” (no) and carrying photos of Mustafa Kemal Atatürk, the founder of the Republic of Turkey and creator of the CHP. According to Radio Free Europe (RFE), at least 3,000 people congregated in Istanbul to protest on Monday, with smaller protests in Ankara and Izmir. All three cities voted “no.”

On Tuesday, in support of CHP representatives entering the headquarters, protesters also gathered outside the YSK building to demand the “no” vote be respected.

A woman holds a banner reading, “Dear respected Ataturk, honesty didn’t work again” as people queue outside the entrance of the High Electoral Board in Ankara, on April 18, 2017, in order to submit their personal appeal for the annulment of the referendum. ADEM ALTAN/AFP/Getty Images

Supporters of the “No voters” and members of Turkey’s main opposition party, the Republican People’s Party (CHP), hold a flag of Mustafa Kemal Ataturk, founder of modern Turkey as they gather at the Caglayan courthouse to submit their petition to object alleged irregularities in Turkish vote on April 18, 2017 in Istanbul. OZAN KOSE/AFP/Getty Images

A supporter of the “No”, wearing a tshirt depicting modern Turkey’s founder Mustafa Kemal Ataturk, gestures and chants slogans during a march at the Kadikoy district in Istanbul on April 17, 2017 to protest following the results in a nationwide referendum that will determine Turkey’s future destiny.BULENT KILIC/AFP/Getty Images

“Thief, murderer, Erdogan,” the protesters chanted, according to RFE. “We are shoulder to shoulder against fascism.”

While the OSCE has condemned the vote, U.S. President Donald Trump called Erdogan on Monday to congratulate him on the victory, according to the state-run Turkish Anadolu Agency.